Every person who answers questions asked in the survey can be called by one name – the respondent. Her or his answers are important because of the purpose of the study. This applies to both those who are completing paper questionnaires, online questionnaires, answer in telephone interviews or who is sharing opinions during the meeting on the face to face interview.

There are different ways of selecting a respondent – sometimes it is a specific group of people, distinguished by some features (eg employees of a given company, habitants of a given country or region), and sometimes respondents are selected using probabilistic research assumptions – random, systematically, in groups or in layers. This type of selection allows for the most representative results.

Depending on the type and purpose of the survey, the respondent may be both one and few, or even hundreds or thousands of people.